I have a 1964 Riviera with a 425. I guess I'm being a little picky but isn't there supposed to be a washer under the wingnut that holds down the top cover of the air cleaner? There are dimples in the area immediately surrounding the bolt hole. It just seems there should be something more than a common wingnut there. Or is the wingnut supposed to have a flat surface on it's bottom that locks into the dimples? I just can't remember. If this is supposed to be different than a commom wingnut, where are the correct ones available ?

The wing nut has a flat washer made on it with dimples on the bottom to match the air cleaner to help ret. the wing nut and air cleaner top. HTH Guyopel :beers:

Thanks guy. I thought I remembered that from the olden days. Ever since I have had my 64 Riv, it has just had a wing nut on it. I removed the air cleaner to repaint it and apply new decals and I took notice of the dimples. When I saw them I new something was wrong.